The City Walls were built in the period 1374 to 1378. They were placed on the foundaion of the wall around the TangDynasty (618-907) .Since the location of Xi'an gives it strategic military importance, the Walls are very tall and were fortified. The eastern wall measures 2.590 metres, the western wall is 2,631.2 metres, the southern wall measures 3,441.6 metres, and the northern wall is 3,244 metres. totalling 11,906.8 metres. Much of the magnificent 600-odd-year-old wall is still standing and it is one of the best examples in China of an outstanding traditional city defense system and urban design.
    The brick city wall forms a rectangle running 3.4 kilometres east-west and 2.6 kilometres north-south. Its circumference is 14 kilometres and it encompasses 11.5 square kilometres. The wall is 12 metres tall; it measures 15-18 metres in width at the base and 12-14 metres on top. On each side there is a city gate, over which the various towers majestically stand. There are four gates such as the East Gate (Everlasting Happiness), the West Gate (Eternal Stability), the North Gate (Pacifying the Outlying Areas) and the South Gate (Eternal Peace). The West Gate (Eternal Peace) is the most impressive. The double gate system played an important role in repulsing enemy attacks. If the first gate were breached, the enemy would still find themselves outside the city wall and would be fired upon from the tower over the inner gate. Together the watchtowers, ramparts, and ninety-eight defense towers form an extremely tight system for military defense of the city.